Atropine is a competitive muscarinic receptor antagonist that is used for its anticholinergic effects. It blocks acetylcholine action in the autonomic nervous system and central nervous system. Atropine is used to treat bradycardia, bronchospasm, asthma, motion sickness, and as an antidote for organophosphate poisoning. Common adverse effects include dry mouth, blurred vision, constipation, tachycardia, and delirium at high doses.

2. • Block the actions of Ach on autonomic receptors
and in the CNS; exerted through muscarinic
receptors.
• Highly selective for muscarinic receptors.
• Synthetic substitutes possess nicotinic blocking
prop. also.

4. Prototype is ATROPINE
Other drugs with anticholinergic
properties
• Tricyclic Antidepressants
• Phenothiazines
• Antihistaminics
• Disopyramide

5. • M1 Antagonists –
Pirenzepine, Telenzepine, dicyclomine,
trihexyphenidyl
• M2 Antagonists –
Gallamine, methoctramine
• M3 Antagonists –
Darifenacin, solifenacin, oxybutynin,
tolterodine

6. • CNS–Atropinehasminimalstimulanteffectson theCNSin
clinicallyusefuldosesandaslower longerlastingsedativeeffecton
thebrain.
• Scopolaminehasmoremarkedcentraleffects, producing
drowsinessandamnesia.
• Intoxicdoses,scopolamineandtoalesser degreeatropinecan
causeexcitement,agitation, hallucinationsandcoma.

8. • Parkinson’sdisease–
• Relativecholinergicexcess,becauseof deficiencyofdopaminergic
activityinbasal ganglia–striatumsystem.
• Acombinationofananti-muscarinicand dopamineprecursor.
• Vestibulardisturbances-
• Esp.motionsickness,involvesmuscarinic cholinergictransmission
• Scopolamine(l-hyoscine)effectivein preventingorreversingthese
disturbances.

9. A) Muscariniccholinoreceptorstimulation
• PupillaryconstrictormuscleStimulation-Blockedbytopicalatropine
• Duetounopposedsympatheticdilatoractivity-Mydriasis
B)Weakeningofcontractionofciliarymuscle
• Cycloplegia
• Lossofaccomodation
• Can’tfocusfornearvision
C)Decreaseinlacrimalsecretions-Dryorsandyeyes

10. • Relative tachycardia
• Low doses – Initial
bradycardia before Ach
block manifests
• Smooth muscles & secretory
glands of airway contain
muscarinic receptors.
• Receptor blockade
leads to
Bronchodilatation &
decrease in
secretions.
• For COPD or Asthma -
antimuscarinic drugs are
effective .

11. • Marked effect on salivary secretions - Dry mouth.
• Motility of git smooth muscles decreases.
• Walls of viscera relaxed.
• Tone and propulsive movements decrease.
• Gastric emptying time – Prolonged
• Diarrhoea due to overdosage of parasympathetic
agents – Stopped

12. Smooth muscles of ureters and bladder wall – relaxed –
voiding is slowed.
Relaxed detrusor muscle
Increased constriction of internal sphincter
Result: urinary retention
• Useful in treatment of spasm by mild inflammatory
conditions and neurologic conditions.
• But precipitation of urinary retention in elderly men with
prostatic hyperplasia, So contraindicated.

13. • Atropineisreadilyabsorbedfromgutand conjuctivalmembranes.
• Scopolamineisabsorbedacrosstheskin, (Transdermalroute).
• Partiallymetabolisedbytheliver.
• Eliminatedprimarilyintheurine.
• Halflifeofabout4hours.

14. A. For Central action
• Parkinson’s disease –
• Benztropine, Biperiden & Trihexyphenidyl used as
adjunctive therapy.
• Motion sickness
• Scopolamine – one of the oldest drug for sea sickness.
• Injection, oral or transdermal (patch behind the pinna ,
prophylactically 4 hrs before journey, effect persists for 3 days
).
• As a lie detector.
• For blocking short term memory, as a useful adjunct in
anesthetic procedures.

15. • As Antisecretory - Glycopyrrolate
• Preanesthetic medication
• When irritant GA is used, before their
administration anticholinergics given to decrease
salivary and tracheobronchial secretion.
• Oxybutinin - to relieve bladder spasm after urologic surgery
e.g. prostatectomy.
• Tolterodine – M3 selective for adult urinary incontinence
Atropine is used in bradycardia , partial heart
block

16. • Peptic Ulcer
• Decrease gastric acid secretion.
• Selective M1 blocker, Pirenzepine,Telenzepine with
decreased side effects.
• When other drugs not effective.
• As Antispasmodic
• Intestinal and renal colic - abdominal cramps
• In the treatment of traveller’s diarrhoea, drug induced
diarrhoea.
• To relieve urinary frequency and urgency.
• Enuresis in children.

17. Primarily, the site of bronchodilation action of inhaled β2-adrenergic
agonists is mainly the bronchiolar smooth muscle. Atropinic drugs
cause bronchodilation by blocking cholinergic constrictor tone,
act primarily in large airways.
Anticholinergics
in asthma
•Ipratropium
•Tiotropium

18. • Ophthalmological disorders
Accurate measurement of refractive error in uncooperative
patients, young children require ciliary paralysis (have high ciliary
tone).
• Retinal examination - when mydriasis is required , So for complete
examination, eye drops or ointment.
• To prevent synechae formation in uveitis and iritis, alternate with a
miotic.
Shorter acting anti-muscarinics (Cyclopentolate and tropicamide)
have largely replaced atropine due to prolonged mydriasis observed with
atropine.
For older children short acting drugs are preferred like
cyclopentolate, tropicamide.

19. Homatropine
Tropicamide

20. • OPC poisoning : 1-2 mg i.v. atropine sulfate
every 5-15 min until signs of dry mouth, reversal
of miosis occurs.
• Some type of mushroom poisoning-
• Massive doses of antagonist may be required
over a long period of time to counteract the
poisons.
• Also blocks the effects of excess Ach resulting
from cholinesterase inhibitors, such as
physostigmine.

21. • Glaucoma patients esp. angle closure.
• Systemic use of moderate doses may ppt.
angle closure.
• In elderly men with caution. Avoided in those
with a history of prostatic hyperplasia.
• Slow gastric emptying may increase
symptoms in patients with gastric ulcer.
• Nonselective anti-muscarinic agents should
never be used to treat acid-peptic disease.

22. • Dry mouth, mydriasis,
• Blurred Vision, dry eyes
• Tachycardia,
• hot & flushed skin,
• Increased Body Temperature,
constipation,
• hallucinations, agitation,
delirium which may progress
to depression,
• collapse of circulatory and
respiratory system, coma and
death.

23. Atropine Poisoning –
Attempt of suicide.
Dry as a bone,
Blind as a bat,
Red as a beet,
Mad as hatter.
Children are very
sensitive to hyper-
thermic effects of
atropine. Death can
occur even with 2 mg.

24. • Temperaturecontrolwithcooling
blankets andseizurecontrolwith
diazepam.
• Physostigmine–smalldosesinslowly i.v.
• Tomanageganglionicblockadewith
markedorthostatichypotension,give
symatho-mimeticagents –
phenylepherine